1. Field of the Invention
This invention relates generally to an imaging recognizing apparatus and in particular to an oscillating tapered slot antenna that scans a field of view transceiving millimeter electromagnetic waves ("MEW") and processing the transceived energy to create a readable image.
2. Discussion
The antenna structures of this invention are capable of creating an image by active or passive operation of the oscillating tapered slot antenna by scanning a field of view. Tapered slot antennas are generally known. However, the flexibly resilient tapered slot antenna of this invention generates a high resolution orthogonal power distributed beam pattern. There is available in the antenna art phased array antenna structures capable of producing a two-dimensional scan through electronic phase shifting elements adjusted in time to yield a two-dimensional scan. For instance such antenna requirements are useful in collision avoidance radar systems for automobiles. Of necessity, such structures are physically quite large, costly to construct and lack in resolution and reliability. Further, they do not effectively sense higher frequencies in a passive mode. Other approaches have been employed to mount parabolic antennas, planar slot antennas or Yagi antennas moveable on gimbles that mechanically provide the necessary sweep of the field of view.
Antenna structures useful for radar applications such as the aforementioned collision avoidance require that they be physically small, that they be able to sense signals in two dimensions, that is 2 D, have a high resolution and broadband characteristics as well as radiation patterns and impedance characteristics that are essentially independent of frequencies over a wide range. The antenna structure of this invention is particularly useful in night vision scanners, robotic devices, it can be used in manufacturing operations, radar-type sensors for automobile collision avoidance having a directional clutter mapping facility.
Accordingly, the antenna structures preferably should be able to synthetically generate two-dimensional direction apertures. In the instant invention the two-dimensional aperture is obtained by oscillating the flexibly resilient tapered slot antenna creating an azimuth deflection and beam weighting. The creation of an azimuth deflection and beam weighting is achieved by a discrete set of elevation scan beams that are modified to have an orthogonal power distribution to each other in the azimuth direction.